<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            width: 300px;
            height: 100px;
            border: 1px solid pink;
            /* 文字水平居中 */
            text-align: center;
            line-height: 100px;
            /* 盒子水平居中 */
            margin: 10px auto;  
        }
        section{
            width: 400px;
            height: 400px;
            border: 1px solid black;
        }
        /* 更改图片的大小设置图片的width height */
        section>img{
            width: 232px;
            height: 164px;
            margin-top: 20px;
            margin-left: 50px;
        }

        aside{
            width: 400px;
            height: 400px;
            border: 1px solid purple;
            background-image: url(https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1591335007495&di=7fdc459fc91ce5dc28c0fab91ef9e1b8&imgtype=0&src=http%3A%2F%2Fpic24.nipic.com%2F20121020%2F10812677_005036136125_2.jpg);
            background-size: cover;
            background-repeat: no-repeat;
        }   
    </style>
</head>
<body>
    
    <div> 文字水平居中  </div>

    <section>
        <img src="https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1591334442958&di=10183635bb5af98898a6a2a89ba77de8&imgtype=0&src=http%3A%2F%2Fimg.ewebweb.com%2Fuploads%2F20190622%2F22%2F1561212361-nLoXlBNuaY.jpg" alt="">
    </section>

    <aside>

    </aside>
</body>
</html>